Halep recorded 12 winners against six unforced errors and broke Sharapova's serve on two occasions to win the match in one hour, 12 minutes.

The 104th-ranked Russian, who returned from a 15-month doping ban in April, was coming off two grueling matches to begin the tournament. She needed three hours to post an opening-round win over Anastasija Sevastova and another two hours, 12 minutes to dismiss countrywoman Ekaterina Makarova on Tuesday.

"I think she played an incredible match, probably the best she's played against me in all of our previous meetings," said Sharapova, who won the China Open in 2014.

"I wasn't as sharp. I wasn't seeing the ball as well. I wasn't moving up and down as well as I have been against her. She was hitting the ball consistently, not making a lot of unforced errors, her service percentage was quite high. She did all the right things. She hit quite deep consistently. When I found myself far from the baseline, I didn't do a good job of coming back in the court. Credit to her, she kept me back there with her consistency."

Halep advanced to set up a rematch against Russian Darya Kasatkina, who defeated her last week at the Wuhan Open.

Third-seeded Elina Svitolina of the Ukraine posted a 6-4, 6-2 win over Australian Ashleigh Barty in their second-round match. The win was the 50th of the season for Svitolina, who took advantage of 36 unforced errors by Barty.

Svitolina advances to face Indian Wells champion Elena Vesnina of Russia for a spot in the quarterfinals.

China's Peng Shuai coasted to a 6-3, 6-2 triumph over Monica Niculescu of Romania to set up a match against Latvian Jelena Ostapenko, who notched a 6-3, 7-5 win over Australian Samantha Stosur in 1 hour, 48 minutes.